Insulin stimulates the proliferation of mouse anterior pituitary cells in vitro

Insulin plays a role in the growth of various tissues. The present study was attempted to clarify the role of insulin in the proliferation of mouse pituitary cells. Insulin stimulated the proliferation of pituitary cells in vitro. E₂ failed to increase the number of BrdU-labelled cells in the absence of insulin, but insulin supplement increased the number of BrdU-labelled cells. Thus, insulin enhanced the responsiveness to estrogen probably at the pituitary cell level. The present results indicate that insulin is closely associated with the pituitary cell growth.